HOW TO REMOVE COMMON INVASIVE PLANTS
Invasive species have adverse effects on our ecosystems. While they’re often pretty, they can choke out native plant species, which reduces the biodiversity of our plants and wildlife. All of this can have a devastating effect on our natural areas. Many invasive species spread very quickly, so it doesn’t take them long to destroy an ecosystem.
Unfortunately, we usually find out the hard way that certain species of plants are invasive, even if botanical experts have preemptively warned governments. But, we can all do our part by removing invasive plants from our yards and keeping our eyes open for them when we’re in natural areas.
In 2019 Indiana Department of Natural Resources put in place the Terrestrial Plant Rule. The list includes 44 different species and makes it illegal to sell, gift, barter, exchange, or introduce any of the listed plants to Indiana.
Here are some of the more common invasive species we see in Indiana, although there are many more. You can view the full list at the Invasive.org site, which includes over 100+ species.
These 7 plants and trees are commonly used for landscaping before their invasive nature became apparent. Here are some tips for how to remove these if they are in your yard.
The Indiana DNR has an invasive plant species resource page for more information about invasive species, how to control them, and alternatives that you can plant.
We have recommended manual removal methods and chemical herbicides here. If you choose to use a herbicide, make sure you read and follow the application instructions very carefully.
Bradford Pear, or Callery Pear, is not on the list of illegal species, but it is invasive. It was popular for a while because it grows fast. But, it spreads fast, wiping out other native species. It is also a very weak tree, making it a safety hazard since it is quite likely to break during storms.
If you have a Bradford Pear, you can start by cutting it down. Unfortunately, it spreads by suckers, so you’re still going to need to keep an eye on it for a few years. If you prefer not to use chemicals, you can just keep a lookout for suckers that come up every year and chop them down once they’re 1-2 feet tall. It will take several years for the root system to exhaust itself, so this is not the most efficient method. If you want a faster way, you may want to consider using a chemical herbicide.
A professional arborist can help you with the removal of Bradford Pears. If you need to pick up a herbicide, our staff at our garden center can help you select the right one.
There are 5 varieties of Honeysuckle on the DNR list, including Japanese, Amur, Morrow’s, Tatarian, and Bell’s Honeysuckles. These varieties of Honeysuckle were popular because they grew fast, and they’re quite pretty. Unfortunately, they choke out everything else.
You can dig small Honeysuckle plants out by hand, removing as much of the roots as possible. This method is quite labor-intensive, and you’ll need to keep an eye out for several years to ensure it is all killed.
The recommended method of removing Honeysuckle is to use a Glyphosate herbicide, more commonly called Roundup. The Roundup should be applied in fall after other plants have died back but before a hard frost. Waiting for other plants to die back will allow you to see the full extent of a honeysuckle invasion. You may need to reapply the herbicide the following year as well. For a smaller invasion in your yard, the safest option may be to cut the plant very short and then paint the herbicide onto the freshly cut end of each stump with a paintbrush. Crossbow is another effective herbicide for Honeysuckle.
Wintercreeper is an invasive evergreen vine that forms a mat, climbs trees, and impedes native species’ growth.
If you prefer not to use chemicals, you can remove wintercreeper by carefully pulling up the vines and disposing them. It may take several years of concerted effort to eradicate it with this method. You can also kill wintercreeper by covering it with cardboard and then 3-5 inches of mulch on top. This mulch will need to stay in place for a minimum of two full growing seasons, and the thicker it is, the better. You can continue to layer cardboard and mulch until it is up to 12” thick to increase effectiveness. Unfortunately, this will also kill any other plants in the area.
If you prefer the chemical method, you can do something similar to the Honeysuckle. Cut it back, usually with a weed wacker, and then paint Roundup onto the stems. If you would instead spray the foliage, you’ll want to use a Triclopyr herbicide as it is more effective as a spray-on for Wintercreeper than Roundup is. Like Honeysuckle, fall is an excellent time to apply these when the weather is above freezing.
Japanese Barberry not only spread fast and choke out other native species, but they also significantly increase the population of ticks that carry Lyme disease, which is not a good thing for us or our pets.
If you prefer to avoid chemicals, you can manually pull out barberry shrubs in the spring. They’re one of the first plants to leaf out, making them easier to identify. However, as with other plants, this method will take a concerted effort over several years to completely eradicate Barberry. Additionally, Barberry has very sharp spikes on the branches, so you’ll need to wear very heavy gloves to protect yourself during removal.
You can also use herbicide on Barberry. Like the other shrubs, your best bet is to cut it down and immediately paint a glyphosate herbicide to the stump.
The Indiana DNR has an invasive plant species resource page for more information about invasive species, how to control them, and alternatives that you can plant.
You can report invasive plants on EDDMaps.org/Indiana. There are also apps for iOS and Android devices that allow you to report as well. The apps also include a list of plants, insects, diseases, and wildlife to help you accurately identify what you are looking at.